Fuse



y 1949' c. c. LAURITSEN 2,

FUSE

Filed April 2, 194:5

INVENTOR CHARLES .0. LAUR/TS 1v ATTORNEY Patented May 10, 1949 UNIEEDi O F l CE;

FUSE;

Charles-oi-Lauritsenpl'asadena Califz, assignor t.- tlfe Uiiited states of Americans representedby the scretarymf 'tlie Navy Appljeatiom-Al'u'iliZ, 1943," Serial No. 481,647

1 Glainw 01. 102-11-76 1 3a This invention relates to iuzesxand imorezpara ti'cularly,,tor a .spririg-armedil imna tfitedinose fiize. of novel. construction which" is-positive and reliable in operation and i may" be ..handle;d :with

safety. Byreason ofitsflsmifig armin i. the new fiize may, be; usedLto particular. advantage..,in rocketpropellediprojectiles; .andlthe likegwheree in.setbackl forces. .alone. are .too .small .to bet em; ployed; safely ,forarmiflg. .andrcentrifugaliforces forarmingare. lacking,

Oneobject. of. the. presentdnvention residesin the .provis'iomnfia nove1..spring?armed fuzeeine cludingsafetp.meansiforulocking.thesnring and.

sleeve-25= is a- -set-back pellet or-- collar 3% which These and otherrzobjects'sof the invention may be better understood by reference to the.ae,com.- panyingdrawing, showing oneform of.,- the new iiize in. longitudinal sectional ..view.

Referring to the drawin ...the.fuze there shown isadaptedgfbr use in verticallyedmppedrair nlane bombs of; the type which isproleeted rearwardly from the airplane by a rocket motor, whereby the bomb strik'es a point substantially in line vertically with the point aofurelease of theihomb from theairplane.

The fuze comprises ageneral-lgcylindrical casing I flawhichds externally.;-threadedlnear its-mankind, asshownzabl I, so thatithercasingtmay beiscrteyved into a suitable receptacle in the nose of the bomb (not shown). Threaded in the rear end of the casing is a container l2 adapted to receive the usual booster charge for detonating the main charge in the bomb. The front end of the booster container I2 is closed by a plate ill in the casing having a central openin l4 communicating with the booster charge. A liner l 5 in the casing abuts at one end against the plate I3 and at the opposite end against a disc I6 seated against a shoulder in the casing, the liner, disc and plate defining a chamber I 5a.

A safety gate I8 is mounted in chamber l5a on apivot l9 "and-is adapted to swing transversely in the chamber on the pivot.- The safety gate is provided witha recess-2n into which therear end of a firing-pin 2| normally extends, the firing pin-projectin throughthe disc-l6: in which it is threaded. The gate l8 isbiased against oneside of-=the firin pin by a spring 22 mounted in a re-. tainer 23 in thegate. A-suitable semi-cap. (not shown) is held in the saiety-gateinoffset rela-, tionto the recesswand the firing pin, and when the-firing pin iswithdrawn fromrecess 26, the gate-is moved-by the spring=22 =.to.an armed posi-, tion in whichthe semi-cap is alinedwith the. firing pin and the opening I l.v Thus, in the armed position of the safety gate, rearward movement of-the firing pin l= explodes the semi-cap and detonatesthe boosterthrough opening 14'.

A- flyWheeLZEdnthe-form:of a sleeve is mounted 0n=the firingpin-in'front of disc [5, the sleeve beingkeyedto'thefirin -pinby a key 26 engaged ina longitudinal slot in-the sleeve. A- helical drivin spring 21 iscoiled aroundthe sleeve between; the disc -l [S and a= flange 28 on the sleeve, -the--innerend of the spring being connected to the sleeve and'thewuterend being anchored in the casingby'a-pin 29.- Slidably mounted on the is: keyed to thesleevebya key 3|. The pellet 30 isi-urged forwardlyagainst a stop 32 on the firing "pin by a compression spring-33 coiled around the sleeve 25- and-seated atone end against flange 28-and-at the'opposite end'against the pellet. It will be understood thatthe firing pin, the sleeve 25and-thesetback pellet rotate as a unit and that the firing pin-"and-pellet are movable longitudinally with respect to the sleeve 25.

The front end-of the casing ill-is closed by a plug 34' which contains, a plunger 35 'slidable transversely of the casing. A ,locking detent 36 on thenplunger' extends rearwardly through a slotin the plug 34* and intoa recess in pellet 30. The plunger 35 is ,urged ,outwardlyin the plug by a-compression springti but is lockeda a nst the spring by a pin 38 movable transversely of the plunger and projecting through the front face of the plug. The pin 38 is normally held in its locking position by a cap 39 on the nose of the fuze casing, the cap being locked on the casing against the action of one or more springs 40 compressed between the cap and the front face of plug 34.

The cap 39 is held against a sealing gasket 42 on the casing by locking means which, as shown, comprises a ring 43 extending around the casing in contact with the edge portion of the cap which 3 is turned outwardly, the ring being made in two or more sections movable radially outwardly to release the cap. An expansible spring 34 extends around the casing inside the ring 43 and acts to separate the sections of the ring, which are held in their locking positions against the spring 44 by an expansible band 45 extending around the outside of the ring. The band 65 comprises two semi-circular sections pivoted at adjacent ends, as shown at 45a, and held together at their opposite ends by outwardly extending tabs 4'5. A headed pin 47 extends through the tabs 45 which are clamped together by a safety wire 45 extending transversely through the pin, the wire being formed with a loop 48a which serves as a handle for withdrawing the wire from the pin, thereby releasing the band 45. When the bomb is mounted on an airplane, an arming wire 49 is inserted through the pin l! to hold the band sections 45 together, and the safety wire 48 is removed. A washer 50 may be inserted between the head of the pin ti and the wire 48.

The front end of the firing pin 2! projects through plug (it into the cap 39. Within the cap is a cross piece 52 keyed to the firing pin and having laterally extendin fingers engaging the locking pin and spring assembly 38- so that the latter prevents accidental rotation of the firing pin when the fuze is being handled. Thus, when the fuze is not in use, the firing pin is locked in its safe position by the locking pin and spring assembly 56-4'0 and by the set-back collar 33 and detent 36. Also, the gate I 8 is held in its safe position by the rear end portion of the firing pin.

The operation of the fuze is as follows: When the bomb is projected from an airplane, the arming wire 49 is withdrawn from pin 4'! to release the band 35 and the ring 43. As a result, the sections of ring 43 are moved outwardly by spring 4-; so as to disengage and release the nose cap 39, and the latter is forced away from the fuze casing by springs 46, thereby removing locking pin 36 and releasing cross-piece 52 on the firing pin. At the same time, the set-back pellet moves rearwardly against spring 33 under the force of set-back incident to acceleration of the bomb by the rocket motor, whereby the set-back pellet disengages the locking detent 36. The spring 37 then moves the detent 36 outwardly on plunger 35, which has been released by the locking pin 38. Accordingly, when pellet 30 is moved forwardly against plug 34 after the force of set-back is dissipated, the detent 35 engages only the peripheral portion of the pellet and cannot lock the pellet against rotation.

The firing pin 2! is now released and is rotated by spring 21 in the sleeve 25, whereby the firing pin is screwed forwardly in the plate I6 and the sleeve so that the rear end portion of the firing pin is withdrawn from gate opening 20. The gate I 8 is then moved by spring 22 to its armed position to aline the semi-cap (not shown) with the firing pin and the discharge opening 14. When the bomb strikes a target, the impact on the exposed cross-piece 52 forces the firing pin to the rear against the semi-cap in gate I8, shearing the threads in plate IS. The semi-cap, therefore, is fired and acts through opening 14 to detonate the booster charge in container I2. It will be apparent that when the firing pin is screwed to its armed position by spring 21, contact between any part of cross-piece 52 and the target actuates the firing pin to explode the semi-cap.

I claim:

A fuze comprising a casing, a flywheel in the casing, a firing pin threaded in the casing and extending through the flywheel, the pin being rotatable with the flywheel and movable endwise therein, a driving spring coiled around the firing pin for rotating the flywheel to screw the pin from a safe to an armed position, a setback collar on the firing pin rotatable with the pin and movable endwise thereon, a, detent engageable in an opening in the collar to lock the pin against rotation, biasing means for urging the collar into locking relation with the detent, the collar being movable against the biasing means by a force of setback to disengage the detent from said opening and release the firing pin, actuating means for moving the detent to an inoperative position wherein the collar and the firing pin are free to rotate, said last means being inoperative when the detent is in said opening, a locking member normally securing the detent against movement by said actuating means and urged toward an inoperative position, a laterally extending element on one end of the firing pin and operable upon impact with a target to actuate the pin for firing the fuze, said element being en-,

gageable with the locking member to secure the firing pin against rotation, a cap on the casing for shielding said element and holding said member in its locking position, and means including an arming wire for securing the cap on the casing and operable by actuation of the wire to release the cap and said locking member.

CHARLES C. LAURITSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,418,606 Swan June 6, 1922 1,895,513 King Jan. 31, 1933 2,030,085 Woodberry Feb. 11, 1936 2,156,471 Denoix May 2, 1939 2,409,205 Graumann Oct. 15, 1946 FOREIGN PATENTS Number Country Date 10,047 Great Britain July 9, 1915 257,335 Great Britain Aug. 27, 1926 267,920 Great Britain Nov. 24, 1927 Great Britain Oct. 10, 1940 

